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You’re exploring Pillar 5: Balance—where a few simple water measurements help protect your comfort, sanitizer and hot tub equipment.

Pillar 5: Balance—Three Numbers That Hold It All Together

What does balancing hot tub water really mean?

Balancing hot tub water means testing its total alkalinity, calcium hardness and pH, then keeping each measurement within the ranges recommended for your hot tub and sanitizer system.

When these measurements are in range, your sanitizer can work as intended, the water feels more comfortable, and the hot tub’s surfaces, heater and other equipment are better protected.

The three balance measurements, in plain English

  • pH — the comfort number. When it’s within the recommended range, the water feels better and your sanitizer can work as intended. When pH drifts too high or low, you may experience irritation, cloudy water, scale or equipment damage.
  • Total alkalinity — the stabilizer. It helps keep pH from bouncing around, which is why you normally adjust alkalinity first.
  • Calcium hardness — the equipment protector. Water with too little calcium can become corrosive, while too much calcium can contribute to scale. Your source water determines the calcium-hardness level you are starting with.

The order that makes it easier

Adjusting the measurements in this order can make the process easier: alkalinity → calcium hardness → pH → then sanitizer. If your hot tub or water-care system provides a different startup sequence, follow its current instructions. We’ll also walk you through the correct ranges and routine when your hot tub is delivered.

Your source water can change

The source water coming from your hose may not be identical at every refill. Seasonal conditions, changes in private wells and adjustments made by municipal water utilities can all affect its starting chemistry.

That is why testing the source water at each refill is more reliable than automatically repeating the chemical amounts used last time.

Learn more: How can the source water for my hot tub change between refills? →

Want to go deeper? Phosphates are one example of something that may enter through source water, runoff, bathers or products used around the home and yard. They matter more to some water-care systems than others.

Explore phosphates in hot tub water →

Want help making sense of the numbers? Artesian’s Island Spas offer WaterLab—an app-guided, probe-based system designed to simplify water testing and adjustments. MinnSpas also provides free 8-parameter water testing at our Apple Valley showroom. Bring in a water sample →

When hot tub water gets tired

Even properly balanced water gradually accumulates dissolved material, including soap, minerals, sunscreen and other residue that normal filtration cannot remove. That is why hot tubs periodically need to be drained and refilled.

The correct drain-and-refill interval depends on the hot tub’s water volume, bather load and water-care system. Follow the directions provided by the hot tub and water-care system manufacturers.

What order should I balance my hot tub water?
Normally, adjust total alkalinity first, followed by calcium hardness, pH and then sanitizer. Alkalinity is addressed first because it helps stabilize pH. If your hot tub or water-care system provides a different startup sequence, follow its current instructions.
Can I fill my hot tub with softened water?
Sometimes, but it depends on the hardness requirements of your hot tub and water-care system. Water that is too soft can become corrosive to equipment. Tell us about your setup and source water before filling, and we’ll help you determine the appropriate approach.
How often should I test my hot tub water?
Follow the testing schedule required by your hot tub, sanitizer system and water-care product labels. Many owners test at least weekly and again after heavy use, but some systems require more frequent testing. Regular testing catches small changes before they become cloudy water, irritation or equipment problems. Water testing at MinnSpas is always free.
Can the source water for my hot tub change between refills?
Yes. Seasonal conditions, groundwater changes, municipal water sources and utility treatment adjustments can affect the water coming from the same hose. Test the source water at each refill instead of assuming it matches the previous one.

You’ve explored all five pillars. Now you can choose a hot tub based on the ownership experience you want—not just how it looks in the showroom.

Return to the Five Pillars overview →

Done exploring the Five Pillars and ready to find an easier-to-care-for hot tub? Let’s build your custom spa setup plan.


Questions? Call or text (763) 200-7727—or bring a water sample to our Apple Valley showroom. Testing is free, and no appointment is needed.

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